Spatial Semantic Expression of Terrain Viewshed: A Data Mining Method

With the rapid development of geographic information technology, the expression of topographic spatial semantic relationships has become a research hotspot in the field of intelligent geographic information systems. Geographic spatial semantic relationships refer to the spatial relationships and their inherent meanings between geographic entities, including topological relationships, metric relationships, etc. These relationships not only reveal the interconnections between geographic entities but also provide an important basis for understanding, analyzing, and applying geographic data. Taking Nanjing's Purple Mountain as the study area, this paper defines a series of attributes representing visual features, quantifies the spatial characteristics of the viewshed, and then uses the DBSCAN algorithm to divide the viewshed into multiple sub-viewsheds, extracting the spatial features of these sub-viewsheds for further analysis. This paper proposes a model for expressing the spatial semantic relationship of the terrain viewshed, which analyzes and describes the spatial features of the viewshed through quantitative and qualitative methods. This model provides theoretical and methodological support for landscape analysis applications based on viewsheds and has good application value in urban planning, environmental ecological protection, archaeological research, and other fields.